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/*
** Copyright 2003-2010, VisualOn, Inc.
**
** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
** You may obtain a copy of the License at
**
** http://www.apache.org/licenses/LICENSE-2.0
**
** Unless required by applicable law or agreed to in writing, software
** distributed under the License is distributed on an "AS IS" BASIS,
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
** See the License for the specific language governing permissions and
** limitations under the License.
*/
/***********************************************************************
* File: pitch_f4.c *
* *
* Description: Find the closed loop pitch period with *
* 1/4 subsample resolution. *
* *
************************************************************************/
#include "typedef.h"
#include "basic_op.h"
#include "math_op.h"
#include "acelp.h"
#include "cnst.h"
#define UP_SAMP 4
#define L_INTERPOL1 4
#define UNUSED(x) (void)(x)
/* Local functions */
#ifdef ASM_OPT
void Norm_corr_asm(
Word16 exc[], /* (i) : excitation buffer */
Word16 xn[], /* (i) : target vector */
Word16 h[], /* (i) Q15 : impulse response of synth/wgt filters */
Word16 L_subfr,
Word16 t_min, /* (i) : minimum value of pitch lag. */
Word16 t_max, /* (i) : maximum value of pitch lag. */
Word16 corr_norm[] /* (o) Q15 : normalized correlation */
);
#else
static void Norm_Corr(
Word16 exc[], /* (i) : excitation buffer */
Word16 xn[], /* (i) : target vector */
Word16 h[], /* (i) Q15 : impulse response of synth/wgt filters */
Word16 L_subfr,
Word16 t_min, /* (i) : minimum value of pitch lag. */
Word16 t_max, /* (i) : maximum value of pitch lag. */
Word16 corr_norm[] /* (o) Q15 : normalized correlation */
);
#endif
static Word16 Interpol_4( /* (o) : interpolated value */
Word16 * x, /* (i) : input vector */
Word32 frac /* (i) : fraction (-4..+3) */
);
Word16 Pitch_fr4( /* (o) : pitch period. */
Word16 exc[], /* (i) : excitation buffer */
Word16 xn[], /* (i) : target vector */
Word16 h[], /* (i) Q15 : impulse response of synth/wgt filters */
Word16 t0_min, /* (i) : minimum value in the searched range. */
Word16 t0_max, /* (i) : maximum value in the searched range. */
Word16 * pit_frac, /* (o) : chosen fraction (0, 1, 2 or 3). */
Word16 i_subfr, /* (i) : indicator for first subframe. */
Word16 t0_fr2, /* (i) : minimum value for resolution 1/2 */
Word16 t0_fr1, /* (i) : minimum value for resolution 1 */
Word16 L_subfr /* (i) : Length of subframe */
)
{
Word32 fraction, i;
Word16 t_min, t_max;
Word16 max, t0, step, temp;
Word16 *corr;
Word16 corr_v[40]; /* Total length = t0_max-t0_min+1+2*L_inter */
/* Find interval to compute normalized correlation */
t_min = t0_min - L_INTERPOL1;
t_max = t0_max + L_INTERPOL1;
corr = &corr_v[-t_min];
/* Compute normalized correlation between target and filtered excitation */
#ifdef ASM_OPT /* asm optimization branch */
Norm_corr_asm(exc, xn, h, L_subfr, t_min, t_max, corr);
#else
Norm_Corr(exc, xn, h, L_subfr, t_min, t_max, corr);
#endif
/* Find integer pitch */
max = corr[t0_min];
t0 = t0_min;
for (i = t0_min + 1; i <= t0_max; i++)
{
if (corr[i] >= max)
{
max = corr[i];
t0 = i;
}
}
/* If first subframe and t0 >= t0_fr1, do not search fractionnal pitch */
if ((i_subfr == 0) && (t0 >= t0_fr1))
{
*pit_frac = 0;
return (t0);
}
/*------------------------------------------------------------------*
* Search fractionnal pitch with 1/4 subsample resolution. *
* Test the fractions around t0 and choose the one which maximizes *
* the interpolated normalized correlation. *
*------------------------------------------------------------------*/
step = 1; /* 1/4 subsample resolution */
fraction = -3;
if ((t0_fr2 == PIT_MIN)||((i_subfr == 0) && (t0 >= t0_fr2)))
{
step = 2; /* 1/2 subsample resolution */
fraction = -2;
}
if(t0 == t0_min)
{
fraction = 0;
}
max = Interpol_4(&corr[t0], fraction);
for (i = fraction + step; i <= 3; i += step)
{
temp = Interpol_4(&corr[t0], i);
if(temp > max)
{
max = temp;
fraction = i;
}
}
/* limit the fraction value in the interval [0,1,2,3] */
if (fraction < 0)
{
fraction += UP_SAMP;
t0 -= 1;
}
*pit_frac = fraction;
return (t0);
}
/***********************************************************************************
* Function: Norm_Corr() *
* *
* Description: Find the normalized correlation between the target vector and the *
* filtered past excitation. *
* (correlation between target and filtered excitation divided by the *
* square root of energy of target and filtered excitation). *
************************************************************************************/
#ifndef ASM_OPT
static void Norm_Corr(
Word16 exc[], /* (i) : excitation buffer */
Word16 xn[], /* (i) : target vector */
Word16 h[], /* (i) Q15 : impulse response of synth/wgt filters */
Word16 L_subfr,
Word16 t_min, /* (i) : minimum value of pitch lag. */
Word16 t_max, /* (i) : maximum value of pitch lag. */
Word16 corr_norm[]) /* (o) Q15 : normalized correlation */
{
Word32 i, k, t;
Word32 corr, exp_corr, norm, exp, scale;
Word16 exp_norm, excf[L_SUBFR], tmp;
Word32 L_tmp, L_tmp1, L_tmp2;
UNUSED(L_subfr);
/* compute the filtered excitation for the first delay t_min */
k = -t_min;
#ifdef ASM_OPT /* asm optimization branch */
Convolve_asm(&exc[k], h, excf, 64);
#else
Convolve(&exc[k], h, excf, 64);
#endif
/* Compute rounded down 1/sqrt(energy of xn[]) */
L_tmp = 0;
for (i = 0; i < 64; i+=4)
{
L_tmp += (xn[i] * xn[i]);
L_tmp += (xn[i+1] * xn[i+1]);
L_tmp += (xn[i+2] * xn[i+2]);
L_tmp += (xn[i+3] * xn[i+3]);
}
L_tmp = (L_tmp << 1) + 1;
exp = norm_l(L_tmp);
exp = (32 - exp);
//exp = exp + 2; /* energy of xn[] x 2 + rounded up */
scale = -(exp >> 1); /* (1<<scale) < 1/sqrt(energy rounded) */
/* loop for every possible period */
for (t = t_min; t <= t_max; t++)
{
/* Compute correlation between xn[] and excf[] */
L_tmp = 0;
L_tmp1 = 0;
for (i = 0; i < 64; i+=4)
{
L_tmp += (xn[i] * excf[i]);
L_tmp1 += (excf[i] * excf[i]);
L_tmp += (xn[i+1] * excf[i+1]);
L_tmp1 += (excf[i+1] * excf[i+1]);
L_tmp += (xn[i+2] * excf[i+2]);
L_tmp1 += (excf[i+2] * excf[i+2]);
L_tmp += (xn[i+3] * excf[i+3]);
L_tmp1 += (excf[i+3] * excf[i+3]);
}
L_tmp = (L_tmp << 1) + 1;
L_tmp1 = (L_tmp1 << 1) + 1;
exp = norm_l(L_tmp);
L_tmp = (L_tmp << exp);
exp_corr = (30 - exp);
corr = extract_h(L_tmp);
exp = norm_l(L_tmp1);
L_tmp = (L_tmp1 << exp);
exp_norm = (30 - exp);
Isqrt_n(&L_tmp, &exp_norm);
norm = extract_h(L_tmp);
/* Normalize correlation = correlation * (1/sqrt(energy)) */
L_tmp = vo_L_mult(corr, norm);
L_tmp2 = exp_corr + exp_norm + scale;
if(L_tmp2 < 0)
{
L_tmp2 = -L_tmp2;
L_tmp = L_tmp >> L_tmp2;
}
else
{
L_tmp = L_tmp << L_tmp2;
}
corr_norm[t] = vo_round(L_tmp);
/* modify the filtered excitation excf[] for the next iteration */
if(t != t_max)
{
k = -(t + 1);
tmp = exc[k];
for (i = 63; i > 0; i--)
{
excf[i] = add1(vo_mult(tmp, h[i]), excf[i - 1]);
}
excf[0] = vo_mult(tmp, h[0]);
}
}
return;
}
#endif
/************************************************************************************
* Function: Interpol_4() *
* *
* Description: For interpolating the normalized correlation with 1/4 resolution. *
**************************************************************************************/
/* 1/4 resolution interpolation filter (-3 dB at 0.791*fs/2) in Q14 */
static Word16 inter4_1[4][8] =
{
{-12, 420, -1732, 5429, 13418, -1242, 73, 32},
{-26, 455, -2142, 9910, 9910, -2142, 455, -26},
{32, 73, -1242, 13418, 5429, -1732, 420, -12},
{206, -766, 1376, 14746, 1376, -766, 206, 0}
};
/*** Coefficients in floating point
static float inter4_1[UP_SAMP*L_INTERPOL1+1] = {
0.900000,
0.818959, 0.604850, 0.331379, 0.083958,
-0.075795, -0.130717, -0.105685, -0.046774,
0.004467, 0.027789, 0.025642, 0.012571,
0.001927, -0.001571, -0.000753, 0.000000};
***/
static Word16 Interpol_4( /* (o) : interpolated value */
Word16 * x, /* (i) : input vector */
Word32 frac /* (i) : fraction (-4..+3) */
)
{
Word16 sum;
Word32 k, L_sum;
Word16 *ptr;
if (frac < 0)
{
frac += UP_SAMP;
x--;
}
x = x - L_INTERPOL1 + 1;
k = UP_SAMP - 1 - frac;
ptr = &(inter4_1[k][0]);
L_sum = vo_mult32(x[0], (*ptr++));
L_sum += vo_mult32(x[1], (*ptr++));
L_sum += vo_mult32(x[2], (*ptr++));
L_sum += vo_mult32(x[3], (*ptr++));
L_sum += vo_mult32(x[4], (*ptr++));
L_sum += vo_mult32(x[5], (*ptr++));
L_sum += vo_mult32(x[6], (*ptr++));
L_sum += vo_mult32(x[7], (*ptr++));
sum = extract_h(L_add(L_shl2(L_sum, 2), 0x8000));
return (sum);
}
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